Characterization of hydrous manganite (-MnOOH) surfaces - an XPS study
2002 (English)In: Surface and Interface Analysis, Vol. 34, no 1, 632-6 p.Article in journal (Refereed) Published
Crystalline manganite (-MnOOH) has been synthesized and characterized using x-ray diffraction and high-resolution transmission electron microscopy techniques. The surface composition was studied with XPS between pH 0.4 and 11. Special pre-cooling procedures were developed to keep the manganite/water interface intact before and during XPS measurements. The O/OH group ratio differs between pH 6 and 11, in agreement with the acid/base characteristics of the surface. Below pH 6, on the other hand, drastic changes can be seen in the O 1s spectra due to dissolution of manganite. Possibly the interaction of OH groups with H+ in acidic suspensions is a first step leading to dissolution. The surface charge arising at high and low pH is compensated by the counter-ions Na+ and Cl-, respectively. The XPS spectra are presented and discussed in terms of the mechanisms for surface complexation and dissolution processes.
Place, publisher, year, edition, pages
2002. Vol. 34, no 1, 632-6 p.
XPS, manganite/water interface, pH dependence, dissolution, sample preparation
IdentifiersURN: urn:nbn:se:umu:diva-9021DOI: doi:10.1002/sia.1376OAI: oai:DiVA.org:umu-9021DiVA: diva2:148692